Ben Baltrusaitis wrote:
I'll be visiting a local shop in a couple
of
weeks that does a lot of
specialty work on the rotary. They are well
know
in the rotary racing world
and have experience building drag cars. Two
options
they offer are "coolant porting and oil
passage porting".
I haven't heard any mention of this on the
list and was wondering if
anyone has any experience in this area or
would
recommend either one or
both. It makes sense to me to improve the
flow,
especially the oil, but I don't want to
risk
any thin walls in critical
areas.
What do all of you think and what should I
be
asking about these
modifications?
Thanks!
Ben
Rumor has it the oil temp can be reduced 10
to
20 degrees by changing
where the oil
comes out out of the block.
Paul Lamar
"Brian D. Cain" wrote:
Hi Ben,
The cooling passage porting is basically the
roughing up of some of the
water jackets around the spark plugs' area on
each
rotor housing. Paul can
tell you more about this and whether or not
it's
actually worth it.
The oil porting thing -> the only thing I can
think of is some work done to
the oil galleys in the front iron housing to
reduce pressure drop points.
There is no chamfering or edging work done on
the
oil galleys once they're
machined. The oil, from the point of the
strainer
to the first oil cooler
line, has to make about 5 or so sharp,
right-angle
turns. Work can be done
to reduce those pressure drop points there.
Another thing that can be done
is enlargening and
smoothing/scuffing/polishing of
the pickup galley where
the oil strainer bolts on. That seems to have
a
positive effect by reducing
the workload of the oil pump and making it
more
efficient.
Depending on how radical you want to go,
there's a
number of things that can
be done.
B
___________________________________________________________________________
Brian D. Cain -/- Dallas/Ft. Worth, TX -/-
bdc196@comcast.net -/-
bdc@bdcmotorsports.com
BDC Motorsports | Performance Rotary Engines,
Haltech EFI Tuning &
Installation, Specialized port work
MSN bdc196@nospam.hotmail.com, Yahoo! bdc196,
AOL
Symajhi, ICQ# 1733105
http://www.bdcmotorsports.com -/-
http://groups.yahoo.com/group/HaltechSupport
In aircraft at less than 100 HP per rotor use
the
ribbing of the internal
water jacket has not been proven necessary.
Perry
Mick and Chuck Dunlap both
flew their engines for hours at 220 to 230 F
with
out apparent harm to the
rotor housings.
Racing Beat is fond of doing it for racing
engines
however.
Here is what it looks like. Racing Beat also
adds an
additional water
port for turbo engines generating over 300 HP
per
rotor. Second picture.
Paul Lamar
Robert LeClercq wrote:
Paul
Where does that aux water port lead to? Also, can
you
please post any pix of your remote water pump
setup.
regards, Robert
Directly into the water passages that go by the
spark plugs.
The water pump is also enlarged.
Paul Lamar
Robert LeClercq wrote:
Paul
Actually, I meant; where does the other end of the new
coolant port connect to?
Robert--
I don't think there is another end. I could be wrong. Jim may have
drilled a few holes in the rear end housing to let some of the increased
flow out of the water jacket. Is that what you are referring to?
BTW just to clarify things cooling requirements are directly proportional
to average HP generated. In other words an aircraft engine running at
85% of peak peak power requires more coolant flow than a car engine idling
around town or going down the freeway at less than 40 HP.
Generally speaking in an aircraft application the stock water pump pumps
the required additional water flow because the water pump is operating at
a higher RPM when the engine is generating more HP. That should be obvious.
However this is not true in a car. An RX8 car can be using less than
40 HP while the engine and water pump is running at 8000 RPM in some lower gear.
Also BTW The water temp has surprising little to do with it. It does not
necessarily follow that a low water temp is cooling the metal rotor housings adequately.
It is possible that an inadequate amount of heat from the metal is being transferred
to the coolant if the flow is too low. You will need the equivalent of a cylinder
head metal temperature gauge to confirm this.
The rotary engine flyers have a lot of successful experience with the stock pump. If you
reduce the flow by using some other, less capable pump, your are taking a large
risk for little or no gain as the stock pump draws less than 3 HP at 7000 RPM.
Vance and I built a water pump dyno so we know.
Paul Lamar
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